Patient interfaces

ABSTRACT

The present invention relates to a device for delivering a supply of gases to a patient. The device includes a patient interface and connecting member. The connecting member is preferably a L-shaped swivelled connector that is capable of being fixed into one of two positions, a first position where the connector is freely rotatable within the patient interface, and a second position where an interference between the interface and connector prevents the free rotation of the connector within the patient interface. The present invention further relates to a connector that has outlet means, which includes at least one outlet vent and a funnel, which in use directs and passes a substantial portion gases expired from the patient through the outlet vent or vents.

BACKGROUND OF THE INVENTION Field of the Invention

This invention relates to patient interfaces, particularly though notsolely for use in providing Continuous Positive Airway Pressure (CPAP)therapy or positive pressure ventilation to patients suffering fromobstructive sleep apnoea (OSA).

SUMMARY OF THE PRIOR ART

In the art of respiration devices, there are well known a variety ofrespiratory masks which cover the nose and/or mouth of a human user inorder to provide a continuous seal around the nasal and/or oral areas ofthe face such that gas may be provided at positive pressure within themask for consumption by the user. The uses for such masks range fromhigh altitude breathing (ie. aviation applications) to mining and firefighting applications, to various medical diagnostic and therapeuticapplications.

One requisite of such respiratory masks has been that they provide aneffective seal against the patient's face to prevent leakage of the gasbeing supplied. Commonly, in prior mask configurations, a goodmask-to-face seal has been attained in many instances only withconsiderable discomfort for the user. This problem is most crucial inthose applications, especially medical applications, which require theuser to wear such a mask continuously for hours or perhaps even days. Insuch situations, the user will not tolerate the mask for long durationsand optimum therapeutic or diagnostic objectives thus will not beachieved, or will be achieved with great difficulty and considerableuser discomfort.

Where such masks are used in respiratory therapy, in particulartreatment of obstructive sleep apnoea (OSA) using continuous positiveairway pressure (CPAP) therapy, there is generally provided in the art avent for washout of the bias flow or expired gases to the atmosphere.Such a vent may be provided for example, as part of the mask, or in thecase of some respirators where a further conduit carries the expiratorygases, at the respirator. A further requisite of such masks is thewashout of gas from the mask to ensure that carbon dioxide build up doesnot occur over the range of flow rates. In the typical flow rates inCPAP treatment, usually between 4 cm H2O and 20 cm H2O, prior artattempts at such vents have resulted in excessive noise causingirritation to the user and any bed partners.

Various approaches have been developed in the prior art to attempt toreduce the noise when CPAP therapy is provided. For example, in PCTPatent Application No. WO98/34665 it has been proposed that the ventinclude a resilient plug with rounded edge apertures to reproduce noise.However, this is not entirely effective in eliminating the extra noisecreated by a vent at the mask.

In common with all attempts to improve the fit, sealing and user comfortis the need to avoid a concentrated flow of air at any portion of therespiratory tracts. In particular with oral masks or mouthpieces it is adisadvantage of prior art devices that the oral cavity may become overlydehydrated by use of the device, causing irritation and possible latercomplications.

SUMMARY OF THE INVENTION

It is an object of the present invention to attempt to provide a patientinterface which goes some way to overcoming the abovementioneddisadvantages in the prior art or which will at least provide theindustry with a useful choice.

Accordingly in a first aspect the present invention consists in a devicefor delivering a supply of gases to a patient comprising or including:

-   -   a patient interface fittable to said patients' nose or mouth,        which in use is in fluid communication with said supply of        gases,    -   connecting member having two ends and interface means, one end        of said two ends being locatable within said patient interface        and the other end of said two ends is connectable to said supply        of gases, said member capable of being fixed into one of two        positions, a first position where said member is freely        rotatable within said patient interface, and a second position        where said interference means prevents the free rotation of said        member within said patient interface.

In a second aspect the present invention consists in a continuouspositive airways pressure system for delivering gases to a patientcomprising or including a pressurised source of gases, transport means,in fluid communication with said pressurised source, adapted to conveysaid gases, and a nasal mask in fluid communication with said transportmeans, in use, delivering said gases to said user, said nasal maskcomprising or including:

-   -   a body portion having an inlet, connected to said transportation        means by a connecting member,    -   sealing means engaged with said body portion, and adapted to        seal against the facial contours of said patient, and    -   securement means attached to or around the head of said user,    -   wherein said connecting member has two ends and interference        means, one end being locatable within said patient interface and        the other end of said two ends connectable to said        transportation means, said connecting member capable of being        fixed into one of two positions, a first position where said        member is rotatable within said patient interface, and a second        position where said interference means prevents the free        rotation of said member within said patient interface.

In a third aspect the present invention consists in a device fordelivering a supply of gases to a patient comprising:

-   -   a patient interface, which in use is in fluid communication with        said supply of gases,    -   connecting member that connects said patient interface with said        supply of gases,    -   outlet means associated with said connecting member, said outlet        means including at least one outlet vent and a funnel, which in        use directs and passes a substantial portion gases expired from        said patient through said at least one outlet vent.

To those skilled in the art to which the invention relates, many changesin construction and widely differing embodiments and applications of theinvention will suggest themselves without departing from the scope ofthe invention as defined in the appended claims. The disclosures and thedescriptions herein are purely illustrative and are not intended to bein any sense limiting.

BRIEF DESCRIPTION OF THE DRAWINGS

One preferred form of the present invention will now be described withreference to the accompanying drawings in which;

FIG. 1 is a block diagram of a humidified positive pressure ventilationsystem as might be used in conjunction with the present invention,

FIG. 2 is an illustration of the nasal mask in use according to thepreferred embodiment of the present invention,

FIG. 3 is a side elevation view of an example of a connector used with abreathing circuit,

FIG. 4 is a perspective view from above of a mouthpiece that may be usedwith the elbow connector of the present invention,

FIG. 5 is a perspective view from one side and from an inward directionof the mouthpiece of FIG. 4,

FIG. 6 is a cross-section of the mouthpiece of FIG. 4,

FIG. 7 is a cross-sectional view of the mouthpiece of FIG. 4 and a userwith the mouthpiece in place to demonstrate the location and positioningthereof in relation to the main features of the patient's anatomy,

FIG. 8 is a perspective view of the mouthpiece with an outer flap inplace,

FIG. 9 is a perspective view of the outer flap bent back,

FIG. 10 is a cutaway view of the mouthpiece with the outer flap in use,

FIG. 11 is a perspective view of the outer flap including theventilation apertures and moisture barrier,

FIG. 12 is a front view of a nasal mask, including a swivelled elbowconnection of the present invention,

FIG. 13 is a side view of the swivelled elbow connection as attached tothe mask body of the present invention in a first position,

FIG. 14 is an exploded side view of the locking mechanism part of theswivelled elbow connection in the first position,

FIG. 15 is a side view of the swivelled elbow connection as attached tothe mask body of the present invention, in a second position,

FIG. 16 is an exploded side view of the locking mechanism part of theswivelled elbow connection in the second position,

FIG. 17 shows a nasal mask body and elbow connector with diffuser,

FIG. 18 shows a cutaway side view of the bias flow director of thepresent invention, and

FIG. 19 shows a cutaway perspective view of the bias flow director ofthe present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention provides improvements in the delivery of positivepressure ventilation therapy. In particular a patient interface isdescribed which is quieter for the user to wear and reduces the sideleakage as compared with the prior art. The patient interface of thepresent invention includes improvements to the swivel elbow connector,bias flow directional funnel and/or elbow diffuser. It will beappreciated that the patient interface as described in the preferredembodiment of the present invention can be used in respiratory caregenerally or with a ventilator but will now be described below withreference to use in a humidified positive pressure ventilation system.It will also be appreciated that the present invention can be applied toany form of patient interface including, but not limited to, nasalmasks, oral masks and mouthpieces.

With reference to FIG. 1 a humidified positive pressure ventilationsystem is shown in which a patient 1 is receiving humidified andpressurised gases through a patient interface 2 connected to ahumidified gases transportation pathway or inspiratory conduit 3. Itshould be understood that delivery systems could also be YPAP (VariablePositive Airway Pressure) and BiPAP (Bi-level Positive Airway Pressure)or numerous other forms of respiratory therapy. Inspiratory conduit 3 isconnected to the outlet 4 of a humidification chamber 5, which containsa volume of water 6. Inspiratory conduit 3 may contain heating means orheater wires (not shown), which heat the walls of the conduit to reducecondensation of humidified gases within the conduit. Humidificationchamber 6 is preferably formed from a plastics material and may have ahighly heat conductive base (for example an aluminium base) which is indirect contact with a heater plate 7 of humidifier 8. Humidifier 8 isprovided with control means or electronic controller 9 which maycomprise a microprocessor based controller executing computer softwarecommands stored in associated memory.

Controller 9 receives input from sources such as user input means ordial 10 through which a user of the device may, for example, set apredetermined required value (reset value) of humidity or temperature ofthe gases supplied to patient 1. The controller may also receive inputfrom other sources, for example temperature and/or flow velocity sensors11 and 12 through connector 13 and heater plate temperature sensor 14.In response to the user set humidity or temperature value input via dial10 and the other inputs, controller 9 determines when (or to what level)to energise heater plate 7 to heat the water 6 within humidificationchamber 5. As the volume of water 6 within humidification chamber 5 isheated, water vapour begins to fill the volume of the chamber above thewater's surface and is passed out of the humidification chamber 5 outlet4 with the flow of gases (for example air) provided from a gases supplymeans or blower 15 which enters the chamber through inlet 16. Exhaledgases from the patient's mouth are passed directly to ambientsurroundings.

Blower 15 is provided with variable pressure regulating means orvariable speed fan 21, which draws air or other gases through blowerinlet 17. The speed of variable speed fan 21 is controlled by electroniccontroller 18 (or alternatively the function of controller 18 could becarried out by controller 9) in response to inputs from controller 9 anda user set predetermined required value (preset value) of pressure orfan speed via dial 19.

Nasal Mask

A nasal mask that nay be used with the improvements to the swivel elbowconnector, bias flow directional funnel and/or elbow diffuser of thepresent invention is shown in FIG. 2. The mask includes a hollow body102 with an inlet 103 connected to the inspiratory conduit 3. The mask 2is positioned around the nose of the user 1 with the headgear 108secured around the back of the head of the patient 1. The restrainingforce from the headgear 108 on the hollow body 102 and the forehead rest106 ensures enough compressive force on the mask cushion 104, to providean effective seal against the patient's face.

The hollow body 102 is constructed of a relatively inflexible materialfor example, polycarbonate plastic. Such a material would provide therequisite rigidity as well as being transparent and a relatively goodinsulator.

The improved swivel elbow connector, bias flow directional funnel and/orelbow diffuser of the present invention may also be used with amouthpiece as described below, or with a full facial mask.

Mouthpiece

Referring to FIGS. 3 to 10 a mouthpiece that may utilise theimprovements to the swivel elbow connector, bias flow directional funneland/or elbow diffuser. In this embodiment, the mouthpiece 50 includes avestibular shield 49 being a generally flat and generallyrectangularly-shaped member in front elevation having a curved profilethat reflects the curvature of a patient's jaw and in turn the curvatureof the labial vestibule region A gases passageway extends through thevestibular shield from an inlet 51 to an outlet 52 in much the same wayas with the earlier embodiments. The inlet 51 is provided by a flattenedoval-shaped connector 53. The outlet 52 has an even more laterallyextended flattened oval shape 54. Most prominently, the mouthpiece 50includes a tongue depressor 55 extending from the inner face of thevestibular shield 49. The operation of the tongue depressor will bedescribed further on with reference to FIG. 5. The tongue depressorincludes a vertical stiffening flange 56 centrally located on its uppersurface and extending from the gases outlet 52. In use gases flow easilyaround the stiffening flange 56 effectively bifurcating the gases outlet52. The tongue depressor 55 further includes a pair of verticallyextending spacers 57, which in use may abut against the roof of thepatient's mouth and ensure that the tongue cannot completely block theair passageway. In the mouthpiece 50 the sealing effect of thevestibular shield 49 against the lips of the user is enhanced byproviding teeth abutments of significantly increased thickness than theraised area 20 of the earlier embodiments. In particular, an upper teethabutment 58 and a lower teeth abutment 59 are provided, with the lowerteeth abutment 59 protruding further from the inner face of thevestibular shield 49 than the upper teeth abutment 58. This differenceserves to match the typical over-bite of most users. The abutments 58and 59 are not required to be wider than the gases outlet 52.

A notch 60 is provided centrally in the upper edge of the vestibularshield 49 to accommodate the upper frenal attachment. A slight bead 61is provided around the edge of the vestibular shield 49 for usercomfort, with the vestibular shield 49 otherwise being very thin foradditional suppleness.

Referring particularly to FIG. 6, the mouthpiece 50 is preferably formedby over-moulding a soft and supple material part 70 over a stiffermaterial part 67. These can generally be termed the shield part and thepassageway-forming insert. The passageway-forming insert preferablyincludes a pair of upper and lower vertical flanges 63 and 64 to fullyengage within the supple material. The passageway-forming insert 67includes the vertically extending stiffening flange 56 of the tonguedepressor 55, together with a curved planar portion 71 forming thebackbone of the tongue depressor 55. The vertically extending spacers 57are of the soft and supple material and are part of the over-moulding70, as are the upper and lower teeth abutments 58 and 59.

Referring now to FIG. 7, use of the mouthpiece according to FIGS. 4 to 6is depicted. With the present mouthpiece 50, the upper and lower lips85, 86 are further distended by the abutment action of the abutments 75,76 against the upper and lower teeth 87, 88 respectively, thus forming aseal of greater pressure between the lips 85, 86 and the upper and lowerportions respectively of the vestibular shield 49. A lower face 77 ofthe tongue depressor 55 impinges if necessary on the upper surface 72 ofthe tongue 85 and retains the tongue in the lower portion of the mouth.This ensures a clear gases outlet 52 from the gases passageway throughthe vestibular shield. The vertically extending spacers 57, if forced bypressure from the tongue, will engage against the roof of the patient'smouth and maintain a clear air passageway. This stops the sleepingpatient unconsciously blocking the oral passageway and reverting tonasal breathing.

Referring now to FIG. 8 of the present invention is illustratedincluding an extra-oral sealing flap 110. The flap 110 in its naturalbias is tapered, the wide-open end of which is shaped to conform to thefacial contours around the outside of the mouth of a user. The narrowend joins to a cylindrical section, which is designed to slide over theinlet port 114 of the mouthpiece 112. While this is one method ofattachment the flap 100 might also be constructed as an integral part ofthe mouthpiece 112. The flap 110 needs to be constructed of flexiblematerial. Therefore, materials such as silicone rubber can be employedto fashion the flap.

The outer flap 110 is seen in FIG. 9, in a bent back position. It willbe appreciated that when the mouthpiece 112 is being inserted into themouth of a users the outer flap 110 is intended to be in this bent backposition to aid insertion. Prior to insertion, the outer flap is bentback by simply pressing on its outer periphery 116, until it snaps intothe bent back position, in which it will stay unaided.

In FIG. 10 we see the outer flap 110 in use with the mouthpiece 112 inthe mouth 117 of a user 120. Once correctly positioned in the mouth 116,the outer flap 110 may be adjusted into its operational position bypressing on its outer periphery 116 until it snaps back to press againstthe outside of the mouth 118. Due to the relative position of thevestibular shield 122 and the outer flap 110, the outer flap 110 isunable to fully reach its natural bias and thereby inflicts acompressive force on the outside of the mouth 118.

It will be appreciated that as well as providing a substantiallyairtight seal the addition of the outer flap provides enough compressiveforce on the mouth to keep the mouthpiece and conduit in place withoutthe need for straps. This allows the administering of positive airwaypressure ventilation therapy to be considerably less obtrusive thantraditional methods.

In a further additional improvement shown in FIG. 11, the outer flap 300is shown in perspective. Included are ventilation apertures 302, 303either side of the gases port 304, which are surrounded by a ridge 306acting as a moisture barrier. The apertures 302, 303 are provided suchthat any excess moisture leaking from the mouth will migrate to theapertures where they may evaporate. Small vents in the conduit may beused to direct small amounts of pressurised gas at the apertures to aidevaporation. The ridge 306 is included to ensure that no moisturemigrates further into the sealing region 308, as this would bedetrimental to the sealing properties of the flap.

Interface Connection

Attention is now directed to FIG. 3. It has been found that anadditional factor in the effectiveness of any patient interface 2, isthe manner in which the interface is connected to the breathing circuit.The weight of the breathing circuit, and any attempted movement of oneother of the breathing circuit and the interface 2 relative to theother, is one of the largest influences tending to dislodge theinterface 2. It must be noted that the interface 2 must remain inposition and maintain a seal during all sleep, when the user has nomuscle tone.

The connection is usually provided between a breathing circuit and aninterface 2, which decouples the interface 2 from the breathing circuit.This type of configuration is shown in FIG. 3, where the interface is amouthpiece, although a nasal mask may be used in place of themouthpiece. The connection 40 is effective in reducing the forces placedon the interface 2 by the breathing circuit 41 when the user movesaround during sleep.

To connect between the gases outlet 42, which is vertical when the useris lying on his or her back, and the breathing circuit 41, which isgenerally horizontal, a L-shaped elbow connector 45 is incorporated inthe connection 40. The elbow connector 45 may be incorporated in theinterface 2. The elbow connector 45 is formed at a right angle andprovides a positive pressure on the interface 2. The elbow connector 45may include a swivel joint and may be disconnected from gaseous outlet42. The connection 40 further includes a connecting tube 46 providedbetween the elbow 45 and the breathing circuit 41. The connecting tube46 is preferably connected to the breathing circuit 41 by a swivel joint48 for reasons described herein. The breathing circuit 41, whileflexible, will necessarily be stiff enough to maintain its inter overcomparatively long tuns, while the flexible connecting tube 46, beingonly a short length, for example 10 centimetres, merely has to spanbetween the patient's mouth and chest, and can thereby be made in amanner that would not be suitable for long runs. Furthermore, as aresult of the short length of the connecting tube 46, the connectingtube 46 does not need to incorporate significant insulation or heatingcapability. The connecting tube 46 may be formed from a thin plasticmembrane supported over helical or double helical or corrugatedsupporting ribs. In such a case, the support makes the connection tube46 laterally flexible and resistant to torsion. The elbow swivelconnector 45 allows for movement of the connection tube 46 relative tothe interface 2. The swivel connector 48 allows for movement of theconnection tube 46 relative to the breathing circuit 41. It is to beunderstood that one or both of the swivel joints 45, 48 could beeliminated, but the preferred embodiment includes elbow swivel connector48.

Fixable Swivel Joint

The nasal mask or mouthpiece as described above can be provided with animproved L-shaped elbow connector similar to that described above.Referring to FIGS. 12 to 16 a L-shaped elbow 401 is fixed to the maskbase 402 on the nasal mask although not shown in the Figures to inlet 51of the mouthpiece 50. Hereinafter when reference is made to “mask body”or “mask base 402” it is intended to refer to either the mask body orinlet 51 of the mouthpiece. A portion 403 of the elbow connector can berotated about a point X in the directions of arrows A and B. The elbowconnector 401 is connectable at its end 404 to the breathing circuit orconduit 3 as described with reference to FIGS. 1 and 2. The connector401 is designed to be fixed into one of two positions and is able to befully removed from the mask base 402. If the connector 401 is assembledin a first position, it is able to freely swivel, as indicated by thearrows labelled A and B on FIG. 12. If the elbow is pushed into a secondposition, an area of interference prevents the connector from freelyswivelling.

Attention is now drawn to FIGS. 13 and 14 where the mask body 501 andelbow connector 502 are shown in a first position where the connector502 is able to freely rotate 360 degrees about a vertical axis out ofthe mask body. The connector 502 is connected to an aperture in thecentre of the mask body, so that in use, gases flow from the breathingcircuit through the elbow connector and aperture in the mask body andinto the patient's lungs. The elbow connector 502 is held within theaperture in the mask body 501 by way of tubular connector 503 located onthe arm of the elbow connector 502. The tubular connector 503 comprisesvarious ridges and protrusions, moulded in the external surface of theelbow connector's arm, that meet with complimentary ridges andprotrusions moulded in the interior surface of the aperture in the maskbody (or the inlet 51 itself).

In particular, referring to FIG. 14, when the connector 502 is in theposition as shown in FIG. 13, the ridge 601 and protrusion 602 in theconnector 502 act with the small ridge 603 and protrusion 604 in theinterior surface of the mask body, to lock the elbow connector 502 intoa position that enables the elbow to swivel freely within the mask body.To remove the elbow 502 from the mask body 501 a force in the directionof arrow C (see FIG. 13) must be placed on the elbow so that theprotrusion 602 on the elbow is forced past the protrusion 604 on themask body, thereby releasing the connector 502 from the mask body.

The elbow connector may be pushed downwards to into the mask body to aposition as shown in FIGS. 15 and 16. Here, the protrusion 602 of theelbow has been pushed past the lower protrusion 802 on the mask body 501and sits within a complimentary ridge 801 in the mask. The protrusion604 on the mask abuts the ridge 601 on the elbow connector and theexterior side surface 804 of the elbow connector above the ridge 601abuts the interior surface 805 of the mask aperture. The area ofinterference 803 between these surfaces prevents the elbow from freelyswivelling within the mask.

The improvements, as described above, to the elbow connector of thepresent invention provides an attachment that can either freely rotate,or be locked in a particular position according to the patient'sdesires. The improvement to the prior art swivel connectors is that theshort flexible tubing (46 as described with reference to FIG. 3) is nolonger required.

Flow Diffuser and Bias Flow Directional Funnel

In an alternative form of the present invention, and in order to reducethe noise caused by expiratory gases being expelled from the mask ormouthpiece, either may be provided with an elbow connector having adiffuser. In prior art systems the flow diffuser is usually providedwithin the elbow connector at the point of connection to the mask bodyor inlet to the mouthpiece, in the present invention it is envisaged toprovide a diffuser on the elbow connector. The following descriptionrefers to nasal mask when describing the diffuser. The diffuser may alsobe provided with an elbow connector used with a mouthpiece as previouslydescribed.

FIG. 17 shows a nasal mask 901 and elbow connector 902 as that has adiffuser located along the length of the connector 902 previously. Theelbow connector 902 includes a diffuser 903 on its exterior surface, thediffuser is a duct that provides for the broadening of the airflow andreduction in the airflow speed. In the preferred form the duct hasoutlet vent holes 904, 905 and the duct is made out of flexible rubbermaterial. Note must be made that any number of vent holes may beprovided in the duct, the preferred form shown in FIG. 17, merely showstwo vents. The duct is preferably provided with a bias flow directionalfunnel, which will be described below.

Referring to FIGS. 18 and 19, during positive pressure ventilationtreatment a portion of the inlet air flow breathed by the patient isexhausted directly through the bias holes 1001, 1002. The only ventingrequired is to clear the expired CO₂ gas from within the elbow connector1003. Therefore a funnel 1004 is provided within the elbow 1003 thatdirects the exhaled CO, gases to the bias holes 1001, 1002 but does notdirect the inlet airflow from the ventilation machine out the biasholes.

The purpose of the funnel is to vent exhaled air from the breathingsystem to remove CO₂ gases. With the prior art breathing systems it hasbeen found that there is continuous leaking of gases through the ventholes during inspiration and expiration by the patient. Therefore, aloss of pressure occurs due to escaping air. Thus, on inspiration thepatient receives less pressure and thus less breathing therapy, andtherefore this requires that vent holes are provided that are as smallas possible to lessen this effect.

During expiration by the patient it is preferred that most of theexhaled gases are vented through the vent holes, in order to preventpressure spikes and to ensure CO₂ gases are expelled from the breathingtubing. The funnel therefore provides for shielding of the vent holesduring inspiration, but enhances the venting of CO₂ gases by providingdirectional flows during expiration, this also allows for vent holes tobe increased in size, providing larger exhaust areas.

Inlet airflow E flows from the ventilating system through the elbowconnector in the direction of arrows F, G and H and into the patient'slungs. The air that is exhaled, as indicated by arrow I, flows throughthe funnel 1004 that has been moulded within the interior of the elbow1003. The funnel 1004 is tubular in shape and provides for thefunnelling of the exhausted CO₂ gases through the outlet bias holes1001, 1002.

Providing such a diffuser on the elbow connector effectively minimisesthe noise generated by the outward flow of expiratory gases from themask. The diffuser of the present invention requires little or nomaintenance and improves user comfort.

The providing of a directional funnel within the elbow connector furtherminimises noise and reduces pressure spikes during exhalation.

1. A device for delivering a supply of gases to a patient comprising orincluding: a patient interface fittable to a patients nose or mouth,which in use is in fluid communication with said supply of gases,connecting member having two ends and means for interference with saidpatient interface, one end of said two ends being locatable within saidpatient interface and the other end of said two ends is connectable tosaid supply of gases, said member capable of being fixed into one of twopositions, a first position where said member is freely rotatable withinpatient interface, and a second position where said means forinterference with said patient interface prevents the free rotation ofthe member within said patient interface.
 2. A device for delivering asupply of gases to a patient according to claim 1 wherein said other endis connected to a conduit that is connected to said supply gases.
 3. Adevice for delivering a supply of gases to a patient according to claim1 wherein said connecting member is a L-shaped connector.
 4. A devicefor delivering a supply of gases to a patient according to claim 1,wherein said means for interference with said patient interface is themeeting of an interference surface on the connecting member that iscapable of abutting said patient interface.
 5. A device for delivering asupply of gases to a patient according to claim 1 wherein said patientinterface is a nasal mask.
 6. A device for delivering a supply of gasesto a patient according to claim 1 wherein said patient interface is amouthpiece.
 7. A device for delivering a supply of gases to a patientaccording to claim 5, wherein said nasal mask comprises or includes: abody portion, having an inlet receiving said supply of gases through agases supply conduit, and sealing means attached to or integrated withsaid body portion, said sealing means adapted to seal against the facialcontours of a patient.
 8. A device for delivering a supply of gases to apatient according to claim 7, wherein said connecting member includesoutlet means, said outlet means including, at least one outlet vent anda funnel, which in use directs and passes a substantial portion of gasesexpired from a patient through said at least one outlet vent.
 9. Acontinuous positive airways pressure system for delivering gases to apatient comprising or including a pressurized source of gases, aconduit, in fluid communication with said pressurized source, adapted toconvey said gases, and a nasal mask in fluid communication with saidconduit, in use, delivering said gases to a patient, said nasal maskcomprising or including: a body portion having an inlet, connected tosaid conduit by a connecting member, sealing means engaged with saidbody portion, and adapted to seal against the facial contours of apatient, and securement means attached to or around the head of apatient, wherein said connecting member has two ends and means forinterference with said body portion, one end being locatable within saidbody portion and the other end of said two ends connectable to saidconduit, said connecting member capable of being fixed into one of twopositions, a first position where said member is rotatable within saidbody portion and a second position where said means for interferencewith said body portion prevents the free rotation of said member withinsaid body portion.
 10. A device for delivering a supply of gases to apatient according to claim 9 wherein said connecting member is anL-shaped connector.
 11. A device for delivering a supply of gases to apatient according to claim 9 wherein said means for interference withsaid body portion is the meeting of an interference surface on saidconnecting member that is capable of abutting said body portion.
 12. Acontinuous positive airways pressure system for delivering gases to apatient according to claim 9 wherein said connecting member includesoutlet means, said outlet means including, at least one outlet vent anda funnel, which in use directs and passes a substantial portion of gasesexpired from a patient through said at least one outlet vent.